This introduces and uses a very simple synchronous mechanism to get /dev/urandom-style bits appropriate for initial KVM PV guest RNG seeding. It also re-works the way that architectural random data is fed into random.c's pools. I added a new arch hook called arch_get_rng_seed. The default implementation uses arch_get_random_seed_long and arch_get_random_long, but not quite the same way as before. x86 gets a custom arch_get_rng_seed, which is significantly enhanced over the generic implementation. It uses RDSEED less aggressively (the old implementation requested 4x or 8x as many bits as would fit in the pool, depending on kernel bitness), but, if using RDRAND, it requests enough bits to comply with Intel's recommendations. x86's arch_get_rng_seed will also use KVM_GET_RNG_SEED if available. If more paravirt seed sources show up, it will be a natural place to add them. I sent the corresponding kvm-unit-tests and qemu changes separately. Changes from v3: - Other than KASLR, the guest pieces are completely rewritten. Patches 2-4 have essentially nothing in common with v2. Changes from v2: - Bisection fix (patch 2 had a misplaced brace). The final states is identical to that of v2. - Improve the 0/5 description a little bit. Changes from v1: - Split patches 2 and 3 - Log all arch sources in init_std_data - Fix the 32-bit kaslr build Andy Lutomirski (5): x86,kvm: Add MSR_KVM_GET_RNG_SEED and a matching feature bit random: Add and use arch_get_rng_seed x86,random: Add an x86 implementation of arch_get_rng_seed x86,random,kvm: Use KVM_GET_RNG_SEED in arch_get_rng_seed x86,kaslr: Use MSR_KVM_GET_RNG_SEED for KASLR if available Documentation/virtual/kvm/cpuid.txt | 3 ++ arch/x86/Kconfig | 4 ++ arch/x86/boot/compressed/aslr.c | 27 ++++++++++ arch/x86/include/asm/archrandom.h | 6 +++ arch/x86/include/asm/kvm_guest.h | 9 ++++ arch/x86/include/asm/processor.h | 21 ++++++-- arch/x86/include/uapi/asm/kvm_para.h | 2 + arch/x86/kernel/Makefile | 2 + arch/x86/kernel/archrandom.c | 99 ++++++++++++++++++++++++++++++++++++ arch/x86/kernel/kvm.c | 10 ++++ arch/x86/kvm/cpuid.c | 3 +- arch/x86/kvm/x86.c | 4 ++ drivers/char/random.c | 14 +++-- include/linux/random.h | 40 +++++++++++++++ 14 files changed, 237 insertions(+), 7 deletions(-) create mode 100644 arch/x86/kernel/archrandom.c -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
